Margot Robbie and Brad Pitt star in Chazelle’s film that revolves around Hollywood in the 1920s as the movie industry shifts from silent films to sound.

Said Hurwitz, “There would be a lot of music in between the parties too, and that would be the pulse of the movie.” “Babylon” features more than two hours of original music, and most of it is Hurwitz’s score.

Justin Hurwitz: The first week of freshman year.

Damien Chazelle: When Justin first called me, he wanted to put together a rock band and he heard I was a drummer.

Hurwitz: I was going around the first week of college asking everybody, ‘Are you a musician? Or do you know a musician?’ I got this tip that this incredible drummer was living in whatever dorm and somebody gave me his number. So, I just called it and luckily he picked up. If he didn’t pick up that first call, I don’t know if I would have had the courage to call back or if I would have found a different drummer.

Chazelle: You would have gotten someone else, and you guys would be making movies.

A Movie like no other?

Chazelle: We wanted to undercut expectations when it came to wardrobe, sets and behavior that you would normally expect from the 1920s.

It all still started from research and trying to locate and imagine what types of costumes and music might have existed at the time, but didn’t get recorded.

We were trying to get a more underground sound, something that would have been wilder than the recording studios would allow at the time. We wanted something full-bodied than the very thin mono recordings that were used.

And it was about making sure Justin felt the freedom to create his soundscape. The real goal was to mix and match and make it feel timeless.

Band playing “Vodoo Mama”?

Hurwitz: Since is set at a party, we wanted the instrumentation of a band that you could believe would be on a bandstand. We had trumpets, a rhythm section and saxes, but made it more aggressive and unhinged.

Many of the tracks in this movie are based around a riff, the kind you would imagine in rock and roll being played on an electric guitar, but instead, we gave that a horn section and the sax is driving the track all the way through.

Collaborative process?

Chazelle: It’s the way we’ve always worked together. I sent him early drafts of the script for him to start churning out musical ideas. Some ideas might have started as piano demos, and he would do small mock-up demos to get a sense of how something would be potentially orchestrated.

By the time that hard prep began, I could start sending those demos to the choreographer who would start working on dance routines. I could start drawing storyboards to create a scrapbook version of the movie.

Love story between Nellie (Margot Robbie) and Manny (Diego Calva)

Hurwitz: We have a Manny and Nellie theme which comes back in different forms. The first version is called “Manny and Nellie’s theme” and it’s a very bittersweet tune. We went around a lot of ideas in terms of finding the instrumentation for it.

In the end, that theme was a blend of three pianos. One is a beautiful Steinway. The second is an out-of-tune, small piano with tacks in the hammers to give it this ‘20s quality, but it’s out of tune and is a little sour. We also had an extremely out-of-tune broken upright piano. When you mix the three, you have the sweetness from the normal Steinway, and then you have different amounts of out-of-tune and broken from the other two pianos. It’s a little sweet and sour, and it feels a little fragile and broken like their relationship.

Jovan Adepo’s character plays the trumpet

Hurwitz: It’s a series of parties and performances, and depending on where we’re at in the story, and where society’s at, the music reflects that.

There’s the unhinged wild party at the beginning. Later, Sidney has a performance where he’s asked to do something very humiliating. And the music is very angry, we’re trying to get at that. With that piece of music, you have a tune at the end that carries us through a bit because it’s a passage of time sequence. It needed to be very reflective and bittersweet.

Impact of “Singin’ in the Rain”?

Chazelle:  It is a very important movie to me. Given the subject matter in this movie, I couldn’t not acknowledge “Singin’ in the Rain.” There’s a whole side of how it came to be is something a lot of people aren’t aware of.

That song was put on film, most notably in 1929 in “The Hollywood Revue” with that weird ensemble number with people in rain slickers in front of a Noah’s Ark backdrop, and that performance had been forgotten and replaced by Gene Kelly.

 Locating the beginnings of that movie and that song, which was a hit song of the period, was one of many attempts that Hollywood was trying to harness sound to something that would get people into theaters. Their approach was that they had sound, so let’s do a musical number. We’ll assemble our biggest stars to do this, it doesn’t really have to make any sense. We’ll grab what’s on the radio, put it together, and boom.

Decades later, once the dust had settled, and there was that transition, Hollywood was able to do a full-hearted look back and lovingly spoof that transition. But the brutality of that transition had been forgotten about so we covered that.

Most of the other songs in the movie “Singin’ the Rain” were written in the ’20s and were a part of the Tin Pan Alley song suite that Arthur Freed and his cohorts were working on at the time. They reappropriated those songs and put them into a movie about that transition in the ’50s.

The idea that the combination of those efforts would be something that one of our key characters would witness, eventually, would ultimately feel a little bit like you were stepping into a movie theater and seeing your own life on the big screen, and the weirdness of that the trauma that goes with it. It’s a reflection of a very difficult memory in his life at that point. But there was also the beauty of that idea and that he was a part of something that lasted.

How the relationship evolved?

Hurwitz: We both want the other to be happy. No one tries to push the other one into something that the other doesn’t like. Damien will never make me do a piece of music that I don’t like, and I’ll never force a piece of music on him. We have disagreements constantly, but when there is and he wants version A and I want version B, we’ll continue looking for version C and we continue to look for that solution

Chazelle: We try to be very honest about what we feel. That combo of being blunt to each other, and never settling either independently or together can make it a longer process, but it ultimately results in something way better.